The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Hammer drills generally include a floating rotary-reciprocatory output spindle journaled in the housing for driving a suitable tool bit coupled thereto. In operation, the spindle can be retracted axially within the housing and against the force of a suitable resilient means, upon engagement of the tool bit with a workpiece and a manual bias force exerted by the operator on the tool. A fixed hammer member can be secured in the housing, and a movable hammer member can be carried by the spindle. The movable hammer member can have a ratcheting engagement with the fixed hammer member to impart a series of vibratory impacts to the spindle in a “hammer drilling” mode of operation. A shiftable member can act upon the spindle to change from a “drilling” mode to the “hammer drilling” mode, and vice versa. In the drilling mode, the cooperating hammer members are spaced too far apart and hence do not engage each other. In the hammer drilling mode, the spacing between the ratcheting teeth is reduced, and the cooperating hammer members impart vibratory impacts to the spindle.
Hammer drills, or more generally, rotary output tools such as power drills can have a transmission that allows a user to shift between multiple output gears to optimize speed and torque for a given application. Typically, the multiple output gears can have various sizes to achieve a desired rotational output. In many cases, a user can shift the transmission to align a desired gear as the driven output gear. Because space may be limited within the housing of such power drills, it can be desirable to optimize the internal component configuration to allow for robust shifting and operation.